I was once seated next to a very large woman, wearing a tank top, who clearly hadn’t showered in a while. It was Honolulu to LA, so only 5 hours (IIRC, but it was over 20 years ago), but it was unbearable. I don’t know how you made it that far without being sick!
How could anyone sit next to someone who stank that bad and not say something to them? I would have no compunctions telling a stranger that they stunk.